About half an hour into last week's The Reunion there was a moment that quite brought me up short, made me stop what I was doing (fannying about trying to get my receipts in order, since you ask). Anna Raeburn, her voice brimming with emotion – rage, regret, upset? – answered a direct question from Sue MacGregor in a direct manner, and what she said was quite a thing to hear. If you haven't already, I think you should hear it too.

The beautifully spoken Raeburn was the buzzing, angry fly in the ointment of this programme. The reunited were five of the founders of the feminist magazine Spare Rib, launched in 1972. Raeburn was the agony aunt: the others were Rosie Boycott, Marsha Rowe, Angela Phillips and Marion Fudger. Mostly they all seemed to get on well: there was a lot of laughter as they reminisced, even when remembering the sexism they encountered. Rowe, who had worked on radical magazine Oz in Australia, recalled how a man there – a groovy hippy type – told her that women could never work like men because they menstruate. Fudger recalled an article about Spare Rib entitled "Six Sexy Girls in London's Naughty Square Mile", and read out its description of her: "Like so many Libbers she is as attractive as she is repellent, as voluptuous as a starlet." She almost spluttered in her indignation, and rightly so.

But then, as MacGregor's opening summary of the state of the female nation made clear, these were different times. In the early 70s women couldn't get a mortgage without the permission of their father or husband, and they could be sacked if they became pregnant. And – I still can't quite believe this – there was a ban on unaccompanied females entering Wimpy bars late at night. Because, obviously, any woman out on her own at that hour was some kind of burger-loving prostitute.

We also heard a recording from El Vino, a Fleet Street watering hole (it's always called a watering hole, by law) where women were not allowed to be served at the bar. The BBC attended a protest against this, where one hack said, "I'm not a misogynist, I like women very much. In their right place."

Spare Rib did some great things, but suffered from tortuous 70s PC-think. Raeburn was sacked because Boycott and Rowe decided that an agony aunt column wasn't politically correct. She was clearly still cross: when Boycott said "we've seen each other a lot since then", Raeburn snapped back that they hadn't: "We've seen each other rather less than 12 times, and you were always fearsome and I was always terrified of you, so nothing's changed."

Reporting this is not to fuel the rubbish that women can't get on with each other, rather to show that speaking your mind – either now or back then – will always rub someone up the wrong way. In the 70s, as Boycott said, "to disagree seemed to threaten the sisterhood" and it simply wasn't allowed. In The Reunion it was, and the programme was fresh and memorable because of it.

Bettany Hughes, whose gender would have hampered her Radio 4 career in the 70s, has been on the station every day this week with her five-part series The Ideas That Make Us. I wish it had been longer, though perhaps it was stymied by its very precise premise. Hughes took a one-word notion that originated in ancient Greece and then tracked it through to today. We got Idea, Fame, Love, Agony and Justice. Idea was the one I liked best. Ideas, we discovered, become astonishingly powerful: they embed themselves in our culture when they acquire a kind of independent authority; they develop a life of their own, no matter how wrong they are. Thus there are still people out there who think the Earth is flat… or that some forms of sexual intercourse are more morally correct than others. Or that dogs are nicer than cats. Or that men are better than women...